The continuing demands for higher performance and higher speed I/O interconnect have resulted in the development of I/O architectures such as the 10-Gigabit Fiber Channel (10GFC), 10-Gigabit Ethernet (10GbE), Peripheral Component Interconnect (PCI) Express and the Infiniband. These I/O architectures implement multiple serial interconnections (known as “lanes”) in order to meet the high data rate requirement and at the same time resolve conspicuous bit-to-bit skew problem present in a high-speed parallel transmission. This solution gives rise to a new set of design challenges, one of which is how to handle lane-to-lane data skews. While the data lanes often transmit data simultaneously, differences in data arrival time are expected at the receiving end due to different path delays and latencies between the lanes. Sources of path delays can be in the chip drivers/receivers, mismatches in routing traces, differences in electrical cable length, differences in serialization/deserialization channels and others. In order to ensure the correctness of the received data, there exists a need to measure the amount of data skews and subsequently compensate for the data skews.
Conventional techniques to measure and compensate for data skews have different concerns. As an example, for conventional absolute lane skew compensation techniques, verification and debugging become complex when data lane count and FIFO depth are increased, which lengthen development time. As another example, for conventional serial deskew compensation techniques, the circuits are difficult to design and require long simulation time due to the extremely high speed circuits involved. In addition, since these circuits are running at some ten times the frequency, power consumption is proportionally high. Other conventional techniques may require training procedures and may be dependent on the I/O architecture.
In view of these concerns, what is needed is a system and method for measuring and correcting data skews that alleviates some of the above-identified concerns.